This invention relates to packaging of primary articles such as cans and bottles in multiple packaged cartons and is more particularly concerned with feeding such cartons from a hopper and for initiating and then completing a loading operation of cartons in sequence.
A majority of known packaging machines are dedicated machines which construct only one type of carton. Therefore, modern bottling plants are required to use a plurality of packaging machines to package different carton types, each machine taking up considerable floor space and being expensive to both purchase and operate.
A limited number of packaging machines are capable of packaging different sizes of one carton, for example, six, eight or twelve bottles of a wraparound carton. All such machines require adjustment when switching from one size or type of carton to another. This adjustment includes the manual removal of all of the cartons within the packaging machine and possibly the mechanical adjustment of components in the machine. During this changeover period, which can be thirty minutes or more, a machine cannot be used (known as xe2x80x9cdowntimexe2x80x9d), which is an expensive delay in a bottling plant. Such a delay may even result in downtime for the entire bottling line, not just the packaging machine, if problems arise during the changeover procedure.
The present invention can be used with a packaging machine described in a corresponding application (applicant""s reference D-7725). It is envisaged that the present invention can be used in various other types of packaging machine. Alternatively, the grouping mechanism of the present invention can be sold as an individual module to be fitted to new equipment or to existing equipment on a retro fit basis.
More particularly, this invention relates to a mechanism for grouping together a plurality of articles from an infeed stream at an infeed end of a packaging machine and is particularly useful for grouping together a plurality of cans or bottles in a multiple packaging machine.
In a known spacer and conveying mechanism disclosed in EP 0 126 553, or EP 0 708 028, a series of spacer elements are spaced apart at fixed locations on the endless chains, each spacer element being configured to engage a plurality of articles from an infeed stream of articles and convey those articles downstream of the machine. The spacing between each spacer element corresponds to the spacing between successive groups of articles. GB A 974 995 discloses a grouping mechanism for grouping articles into package units which comprises a first pair of chains which have lugs spaced apart at fixed intervals for engaging articles at an infeed end of the apparatus. The pair of chains are mounted on opposite sides of a pair of fixed support plates which together with the lugs cooperate to divide the array of articles at the infeed into groups of fixed separation and propel the groups towards a second pair of chains also having lugs spaced apart at fixed intervals. The second pair of chains has a greater downstream velocity compared to the first pair of chains. The upstream article of a group of articles is engaged by a lug of the second pair of chains thereby forcing the groups of articles forward at a greater speed than that determined by the first pair of chains.
The present invention seeks to overcome the commercial disadvantages of known packaging machines and spacing mechanism by providing a grouping mechanism which is able to group articles for loading into more than one type of carton. Further, the invention is capable of switching from one configuration of grouped articles to another for loading into different carton types or sizes with minimum downtime. Further, the modular nature of the present invention enables a fully flexible machine to be constructed which overcomes, or at least mitigates, the problems of known machines.
One aspect of the invention provides a grouping mechanism for grouping articles to be loaded into a carton and delivered to the mechanism from an infeed stream at an infeed end of a packaging machine, which mechanism comprises a pair of opposed spacer elements, each spacer element adapted to engage at least one article from the infeed stream and to convey the article through a working reach of the mechanism and transfer means being provided to return each spacer element along a return reach such that they are returned upstream of the working reach. There further comprises adjustment means to increase the spacing between said opposed spacer elements whereby a third article intermediate and juxtaposed said engaged articles in conveyed by said spacer elements.
According to yet another optional feature of this aspect of the invention, the third article may lead the engaged articles during the working reach and wherein article alignment means may be provided to move the third article into lateral alignment with the engaged articles when the engaged articles are disengaged from the spacer element.
According to still another optional feature of this aspect of the invention, the article alignment means may be provided by opposed panels of the carton in contact with the articles to guide the articles into alignment.
According to another optional feature of this aspect of the invention, there may further comprise adjustment means to adjust the spacing between the spacer elements to receive two or three rows of articles.
According to an optional feature of this aspect of the invention, the spacer element comprises a part cylindrical recess to receive a portion of the article being conveyed.
According to a further optional feature of this aspect of the invention each spacer element may be mounted on a cam track, wherein each cam track provides a path for the spacer elements to maintain the recesses parallel to the articles during the engagement.
According to an yet another optional feature of this aspect of the invention the spacer element may further comprise a second part cylindrical recess to receive a portion of a second article to be conveyed in a grouped arrangement with the first article.
According to another optional feature of this aspect of the invention regulating means may be provided to control the flow of articles at the infeed end, the regulating means further comprising means to control the pressure of the articles into the machine and means to determine the correct number of articles for each carton.
According to yet another optional feature of this aspect of the invention the means to control the pressure of the articles comprises an infeed star wheel.
A second aspect of the invention provides a method of grouping articles delivered from an infeed stream of a packaging machine which method comprises engaging successive articles with spacer elements from the infeed stream so that those articles are located relative to one another during feed movement of the articles so that one group of articles becomes advanced with respect to and thereby spaced from the next succeeding group of articles while the spacer elements move along the feed path of the articles and thereafter, returning the spacer elements upstream such that they are appropriately spaced one from the next for engagement with successive articles in the infeed stream. The group of articles comprise two outer rows advanced by the spacer element and a central row intermediate the outer rows, each row having at least one article and further comprising the step that the central row abuts a leading portion of an article of each advancing outer row thereby to advance the central row.
According to still another optional feature of this aspect of the invention, after the articles leave engagement with the spacer elements there may further comprise the step of moving the outer rows and central row into lateral alignment for loading into a carton.